Flux-Activate co-simulation: preparation of the Flux project


Co-simulation requires that the standard description (geometry, mesh, physics) of the Flux project has been done. To prepare the coupling between Flux and Activate, it is necessary to define, in Flux, the desired input and output parameters, in order to generate a coupling component file.

Flux Inputs

Several types of quantities can appear amongst the input parameters :

  • electrical quantities (ex. resistance, voltage, current…)
  • mechanical quantities (ex. torque, speed, position,…)
  • geometric (air gap,…)

As the coupling between Flux and Activate uses multiphysics co-simulation, the input parameters must be defined as I/O Parameters of multiphysics type.

Flux Outputs

We can find the exact same quantity types as with the input parameters; namely the electrical, mechanical and geometric quantities. The output parameters must not be of the multiphysics type.

An output parameter can be:

  • a geometric parameter
  • a I/O non multiphysics parameter
  • a predefined parameter of a mechanical set
  • a sensor

The coupling component

The coupling component file is necessary in order to ensure the transfer of information from the Flux project to Activate. This component data is described in the *.F2STA file. Once the necessary input and output parameters for the coupling have become available, the user must generate a component:

  • by clicking on the Generate component for Activate coupling in the Solve menu.
Having generated the coupling component :
  • A file ComponentName.F2STA is created (by default in the current directory).
  • A Flux project ComponentNameF2STA.FLU is created and it should have the same name as the .FLU accessed from Activate during the solving process.

Upon launching of the solving process via Activate, the corresponding project Flux is registered with the following name:


*.F2STA file

This file contains the information necessary for Activate to be able to automatically detect:

  • the version of Flux
  • the version of F2STA
  • the numerical memory
  • the character memory
  • the project dimension (2D or 3D)
  • the inputs and the outputs

Solving Scenario

No solving scenario defined in Flux will be taken into consideration by Activate. Activate forces Flux to perform a computation during the co-simulation.

Multiphysics position kinematic model

For the Flux-Activate co-simulation with an electric machine, the type of the mobile mechanical must be Multiphysic position. In this case, the position is imposed by the Input/Output variable called ANGPOS_name_of_mechanical_set (for instance ANGPOS_ROTOR, for a mechanical set in rotation called ROTOR). This variable is created automatically after having created the mechanical set. It allows managing the solving of mechanical equation on Activate side, which gives more flexibility in the definition of mechanical equation.